1. Field of the Invention
The present invention relates to a gyroscope for sensing an angular velocity using a rotational resonance motion of a mass moving in a regular angle. More particularly, the present invention relates to a rotary gyroscope capable of sensing a plurality of angular velocities corresponding to a plurality of axes in a plane.
2. Description of the Related Art
Generally, a gyroscope detects a rotational angular velocity by changing a displacement of a mass due to a Coriolis force into a change in capacitance, based on a principle that when a mass oscillating or rotating in a direction of a first axis is applied with a force of rotating in a constant angular velocity from a direction of a second axis, which is normal to the first axis, the Coriolis force acts on the mass in a direction of a third axis, which is normal to both the first axis direction and the second axis direction.
Such a gyroscope is currently in use as a core part for precision navigation in ships and airplanes. Recently, developments in micro-electromechanical system (MEMS) technology have enabled the application of a gyroscope in a navigation device of automobiles and as a hand-oscillation compensating device of high performance video cameras.
Although there are conventional micro-gyroscopes that can measure an input angular velocity normal to a center plane thereof, which may be easily fabricated and driven, these conventional micro-gyroscopes have a disadvantage in that they are not able to detect angular velocities of more than two axes in a plane.
More specifically, if the micro-gyroscopes were to be used in sensing angular velocities of a plurality of axes, elements such as a sensing mass and a driven mass should be vertically disposed. Such a configuration requires an additional assembling process for vertically disposing the elements and a size of the micro-gyroscope is increased.
In an effort to solve these problems, other conventional micro-gyroscopes have been proposed that are capable of sensing angular velocities of a plurality axes in a plane. These other conventional micro-gyroscopes, however, present several varying problems. For example, these conventional micro-gyroscopes may experience problems with one or more of the following: difficulties in adjusting a driving and sensing frequencies due to a coupling of a driven unit including a driven mass and a motion of sensing unit including a sensing mass, adhesion between the sensing mass or sending unit and a sensing electrode, deterioration of performance due to a weak levitation force, decreased sensing motion, deformation of a sensing mode, or a relatively complicated fabrication processes.